Expandable stents and method for making same

Abstract

The invention is directed to an expandable stent for implantation in a body lumen, such as an artery, and a method for making it from a single length of tubing. The stent consists of a plurality of radially expandable cylindrical elements generally aligned on a common axis and interconnected by one or more interconnective elements. The individual radially expandable cylindrical elements consist of ribbon-like material disposed in an undulating pattern. Portions of the expanded stent project outwardly into engagement with the vessel wall to more securely attach the stent.

What is claimed is: 
     
       1. A longitudinally flexible stent for implanting in a body lumen, comprising: a plurality of cylindrical rings having an undulating pattern in the form of peaks and valleys and being adapted for expansion from a first delivery diameter to a second expanded diameter;   the plurality of cylindrical rings being aligned on a common longitudinal axis and each cylindrical ring being connected to an adjacent cylindrical ring by interconnecting elements; and   the interconnecting elements forming a three point connection at either the peaks or the valleys of the undulating portion.   
     
     
       2. The stent of claim 1, wherein there are at least three interconnecting elements between adjacent cylindrical rings. 
     
     
       3. The stent of claim 1, wherein there are at least two interconnecting elements between adjacent cylindrical rings. 
     
     
       4. The stent of claim 1, wherein there is at least one interconnecting element between adjacent cylindrical rings. 
     
     
       5. A longitudinally flexible stent for implanting in a body lumen, comprising: a plurality of cylindrical rings having an undulating pattern in the form of peaks and valleys and being adapted for expansion from a first delivery diameter to a second expanded diameter;   the plurality of cylindrical rings being aligned on a common longitudinal axis, and having a first end cylindrical ring and a second end cylindrical ring, each of the cylindrical rings being connected to an adjacent cylindrical ring;   a plurality of projecting edges forming on at least the cylindrical elements between the first end cylindrical ring and the second end cylindrical ring as the stent is expanded from the first delivery diameter to the second expanded diameter.   
     
     
       6. The stent of claim 5, wherein the cylindrical rings are connected by at least three interconnecting elements between adjacent cylindrical rings. 
     
     
       7. The stent of claim 5, wherein the cylindrical rings are connected by at least two interconnecting elements between adjacent cylindrical rings. 
     
     
       8. The stent of claim 5, wherein the cylindrical rings are connected by at least one interconnecting element between adjacent cylindrical rings.